Atherosclerosis, the underlying disease implicated in myocardial infarction and strokes, is a complex pathologic process involving the intimal layer of the arteries. The earliest lesion of atherosclerosis is development of the fatty streak lesions which contain lipid-laden macrophages and lipid-laden smooth muscle cells. Macrophages do not take up native low density lipoprotein (LDL) but do take up modified, i.e., acetylated LDL or oxidized LDL via acetyl-LDL or "scavenger" receptors to form the foam cells of atherosclerotic plaque. Free radial oxidation, i.e., lipid peroxidation, has been shown to be involved in the alteration of LDL by endothelial cells. Arterial smooth muscle cells generate superoxide and oxidize LDL in the presence of micromolar concentrations of Cu.sup.+2 or Fe.sup.+2. The way LDL can be modified by endothelial cells can be mimicked in vitro by incubation of the lipoprotein in the presence of CuCl.sub.2. Probucol, an antihyperlipidemic agent, also inhibits both cell mediated and Cu.sup.+2 mediated oxidative modification of LDL, and was shown to inhibit the formation of atherosclerotic lesions in WHHL rabbits [Reaven et al., Arteriosclerosis and Thrombosis 12(3),318-324 ( 1992), Steinberg, The Amer. J. of Cardiology 57, 16H-21H (1986), Carew, Schwenke and Steinberg, Proc. Natl. Acad. Sci. 84, 7725-7729 (1987) and Nagano et al., Arteriosclerosis 9 (4), 453-461 (1989)]. Thus in vitro inhibition of Cu.sup.+2 catalyzed oxidation of LDL is indicative of antiatherosclerotic utility.
The published unexamined Japanese patent application 4,117,341 discloses compounds of the formula: ##STR2## wherein R.sup.1 and R.sup.2 are lower alkyl and R.sup.3 and R.sup.4 are hydrogen, carbonyl, carboxy, lower (halo)alkyl, lower alkoxycarbonyl, lower alkoxycarbonylalkyl, lower hydroxyalkyl, phenylthio, phenyl optionally substituted with 1-3 substituents selected from OH, halogen, lower alkyl, and lower alkoxy, 4-R.sup.5 -piperazinyl-A- where R.sup.5 is lowerhydroxyalkyl, phenyl optionally substituted with 1-3 substituents selected from halogen, lower hydroxyalkyl, lower fluoroalkyl and lower alkoxy and A is carbonyl or loweralkylene or R.sup.3 and R.sup.4 together forms an alkylene chain. These thiazoles, some of which are similar to the oxazole compounds of this invention, are disclosed to have antiinflammatory, antirheumatic, and ischaemic re-perfusing disturbance ameliorating action.